Servers and Workstations

Workstations

C&CZ manages (for departments) workstations with Ubuntu Linux or MS-Windows. There are also workstations in the PC-rooms and Study area for general use by anybody with a Science login, but also by all RU employees and students and guests with a temporary login. Almost all those machines are dual boot, the user can choose to boot Ubuntu Linux or MS-Windows.

Linux login servers

Two secure shell servers are available for Students and Staff of the Faculty (everyone with a Science account). The primary login server can be reached with the following address:

lilo.science.ru.nl

The name of the backup login server is:

stitch.science.ru.nl

At the moment, lilo points to a machine called lilo4. Stitch points to lilo3.

In case you are behind a firewall that does not permit outgoing connections to the standard ssh port 22: our login servers also allow ssh connections to ports 80 and 443.

Windows terminalserver

Some applications require a PC with MS Windows installed. If you use another operating system, you can make use of a Windows Terminal Server.

Compute servers/clusters

C&CZ manages a number of compute clusters, with compute nodes that departments have purchased. In a few cases, departments have created a separate cluster by also purchasing their own head node (master). The largest cn-cluster also has a node purchased by C&CZ, so FNWI departments may use that after approval by C&CZ.
For departments of FNWI the housing and management of clusternodes is free of charge. The cn-cluster is heterogeneous. The newest nodes have SLURM as cluster software, other nodes wil be moved from Torque / MAUI to SLURM. In 2006 the cluster started with Fedora Linux and Sun GridEngine as previous clustersoftware. As of October 2015, the cn-cluster totalled 1220 cores and 8266 GB RAM. Several clusternodes have a GPU with CUDA cores. The CPU-load of the clusternodes is being monitored.

Sometimes outside of opening hours also the pcs in the computer labs are used as a compute cluster.

Mail server

On the Do-It-Yourself website each user can see which mail server will store incoming mail for his account. Mail can be accessed with IMAP over SSL. The use of POP3 is supported, but not advised. In every domain managed by C&CZ the alias smtp.science.ru.nl points to the machine that accepts mail with the SMTP-protocol. N.B.: If one uses a (non-RU) Internet provider, our mail server will only accept mail for our (RU) mail-addresses. Most other mail will not be accepted ("Relaying Denied!"). One can prevent this by using the smtp-server of the Internet-provider or by using Authenticated SMTP.

WWW servers

Printer servers

Several servers are used to print jobs. See the printer webpage to see which server is advised in which situation.

Disk servers

These servers share different types of files, e.g. home-directories, application-software and disks for departments and groups. All modern servers only have redundant disks, sometimes by using "mirroring", sometimes by use of a "RAID-array". That means that loss of only 1 disk will not cause any problem for users.

by logging in to a login server like lilo in /vol/ftp/pub/yourdirectory.

by attaching the network drive: \\ftp.science.ru.nl\ftp

By using an unreadable upper directory containing a secret directory, one can even transfer somewhat sensitive data.

License servers

For several software packages there is a license server, that allows use of the software on all pc's, while making sure that the total number of licenses uses is not more than what has been bought. Most of these license servers use FlexNet by Flexera.

Backup servers

Almost all disks that are managed by C&CZ, are being backupped regularly, in order to be able to restore data in case of small or large calamities.